Usually, for the purpose of exhibiting high performance, a rare-earth magnet to which a rare earth such as neodymium or dysprosium is added has been used as a magnet for a motor.
PTL 1 discloses an axial type motor having a rotor fitted with plural permanent magnets having magnetic poles in a parallel direction to a rotary shaft.
Moreover, PTL 2 proposes a high-performance axial gap motor having a ferrite magnet instead of the rare-earth magnet.
The axial type motor or axial gap motor has a rotor on which a magnet is disposed and the magnet is supported by a support included in the rotor. As the support, there is generally used a nonmagnetic steel composed of an austenite stainless steel.
The support is included in the rotor that rotates at a high speed, and it is necessary for the support to support the magnet to keep its position appropriately. Therefore, it is necessary for the support to have not only a nonmagnetic property but also an appropriate strength.
Incidentally, the austenite stainless steel exhibits increased strength through cold working, but there is a problem that the nonmagnetic property is impaired by strain induced transformation. Therefore, there is usually adopted a step of subjecting a raw material after hot forging to machining to obtain a support shape.